Apparatus for comminuting grain

ABSTRACT

Am apparatus for comminuting grain in which a feed rotor entrains the grain along its underside and propels the grain at high velocity against blades rotated in the opposite direction on a comminuter rotor which cooperates with fixed teeth attached to the housing walls.

United States Patent Inventor Toni Golubinov Tassev Sofia, BulgariaAppl. No. 831,468 Filed June 9, 1969 Patented July 27, 1971 Assignee DSPBulet Sofia, Bulgaria Priority June 11, 1968 Bulgaria 101 14 APPARATUSFOR COM MINUTING GRAIN 2 Claims, 3 Drawing Figs.

U.S. Cl 146/123,

241/154,241/186 Int. Cl. H. B02b 3/08, B02c 13/09 Field of Search146/123;

[56] References Cited UNlTED STATES-PATENTS 1,861,779 6/1932 Bornhauser1,840,893 1/1932 Giddings 3.436028 4/1969 Koehnen et al FORElGN PATENTS791,927 10/1935 France 27,635 4/1955 Finland 1,157,062 11/1963 GermanyPrimary Examiner-Andrew R. Juhasz Assistant Examiner-Z. R. BilinskyAt10rney- Karl F. Ross ABSTRACT: Am apparatus for comminuting grain inwhich a feed rotor entrains the grain along its underside and propelsthe grain at high velocity against blades rotated in the oppositedirection on a comminuter rotor which cooperates with fixed teethattached to the housing walls.

PATENTED M27 :97:

TONI GOLUBINOV TASSEV INVEN'I'OR.

APPARATUS FOR COMMINUTING GRAIN The invention relates to an apparatusfor comminuting grain and, more particularly, to an inertial breaker forsubdividing grain, e.g. to obtain a flour fraction.

inertial breakers for commin uting grain have been provided heretoforewith movable or immovable striking bodies to which the grain is fed. Ingeneral, the grain flows freely to the impact members which engage thegrain and break it up prior to passage of the grain through a sieve.Particles which do not pass through the screen are further comminuted bya hammer or blade. It has been found that this system yields aheterogeneous product made up, as is apparent, by the particles whichfreely pass through the sieve and particles which are crushed throughthe latter.

The rotors used for these purposes are complex and are not subject toeven wear so that balancing them creates a dilficulty.

it is an object of the present invention to provide an improvedapparatus for comminuting grain.

This object is achieved, in accordance with the present invention, byproviding an impact rotor drum, fitted with externally projectingtoothed blades and rotated in one sense while a counterrotating feedrotor constitutes an impeller entraining the grain between the rotorsand in the direction of the blades at high velocity. As a result of theimpact of the grain upon the blades, the relative speed of each grainand the impact surface is increased and improved grinding is carriedout. The fraction of undesirable flour may be reduced to 20 percent andit is possible to obtain a homogeneous product without a sieve.

The above and other objects,'features and advantages of the presentinvention will become more readily apparent from the followingdescription, reference being made to the accompanying drawing in which:

FIG. 1 is a vertical section through the apparatus of the presentinvention;

FIG. 2 is a cross section illustrating how the blades of the impactrotor are affixed to the rotor body; and

FIG. 3 illustrates a detail view of the repellers carried by thehousing.

From the drawing, it will be apparent that the grain-breaker apparatus,as distinct from a crushing device, comprises a housing 1 rotatablyreceiving a feeding rotor or impeller 2, a regulator or guide 3 forpassing the grain at a controllable rate along the underside of theimpeller 2 and an impact rotor 5 which is also rotatably mounted in thehousing. The rotor 5 is formed along its periphery with angularly spacedarrays of radially projecting toothed knives or blades 6 of generallytrapezoidal configuration. Along the path of the working rotor 5 andespecially of grain projected thereby to the left, there are providedarrays of toothed repellers 4 affixed to the housing 1. The toothedrepellers 4 thus constitute fixed blades (FIG. 3) which intercept thegrain particles cast in the counterclockwise sense by the rotor 5 andcooperate with the latter to further comminute the grain. The feedingrotor or impeller 2 is mounted on the shaft of an electric motor (notshown) and is driven at about 3000 r.p.m., the periphery of the rotor 2being provided with fan blades to facilitate the projection ofthe graintangentially into the path of the counterrotating rotor 5. The latter ismounted on the shaft of another electric motor (not shown) with the samerotary speed, i.e. 3000 r.p.m.

On the periphery of the drum of the rotor 5, are formed trapezoidalslots (FIG. 2) in which the toothed blades 6 are fitted and separated byadjusting lamellas 7, the thicknesses of which determine the clearancebetween the blades 6 and hence the particle size of the comminutedgrain. The regulator 3 comprises a steel surface running along theperiphery of the rotor 2 and the entire throat of the breaker and whichcan be adjusted toward and away from the latter via an adjusting slot,to control the rate at which grain is fed through the device.

As can be seen from FIGS. 1 and 3, the toothed repellers 4 may beattached to the housing in such manner that they can rotate about theiraxes for ad ustment and to replace wornout teeth. The grains enter thepath of the feeding rotor at high speed and are entrained in thecounterclockwise sense along the underside of the rotor and areprojected tangentially from the latter into the path of thecounterclockwise rotating member 5. The stream of grain is thustangential to the opposite side of rotor 5 from that at which the grainleaves the rotor 2 and hence encounters the blades 6 as the latter movein the opposite direction. By reason of the acceleration imparted to thegrain by the rotor 2 and the countermovement of the blades 6, the grainpasses into the path of these blades at a relative speed much higherthan is obtainable with conventional systems. Upon impact of grain withthe blades, the grain is subdivided into small pieces and a smallpercentage of undesirable flour fraction. The grain particles areentrained by the blades through the arrays of repellers 4 and finallyare projected at high velocity upwardly out of the apparatus. Theapparatus, of course, operates without a sieve, has a simplifiedconstruction since it omits the sieve and bearings and belts commonlyused in other apparatus. The wear of the blades is less so that theylast longer than the blades of conventional hammers and the profileblade 6 has been found to have improved efficiency.

lclaim:

1. A grain comminuter comprising a housing formed with a grain inlet; animpeller rotatably mounted in said housing for projecting grain in onedirection along a path; an impact rotor mounted rotatably in saidhousing and formed with a peripheral array of outwardly projectingblades displaceable on' said rotor to intercept said path and rotatablein a direction opposite the direction in which said grain is projectedby said impeller; and at least one array of repeller blades attached tosaid housing for intercepting grain entrained by said impact motor andcooperating therewith to comminute the grain.

2. The grain comminuter defined in claim 1 wherein said impeller is arotor provided with fan blades and is rotated in one sense for sweepingsaid grain along one side of the impeller rotor, 'said comminuterfurther comprising a regulator extending from said opening along saidside of said impeller for controlling the rate of flow of the graintherethrough, said impact rotor being formed along its periphery withangularly spaced slots, each receiving an array of toothed impact bladesseparated by spacer lamellae establishing the distance between thetoothed blades, said impact rotor being positioned to bring the sidethereof opposite the side of the impeller rotor into engagement with thegrain, said repeller blades being rotatably adjustable to replace theeffective cutting edges thereof.

1. A grain comminuter comprising a housing formed with a grain inlet; animpeller rotatably mounted in said housing for projecting grain in onedirection along a path; an impact rotor mounted rotatably in saidhousing and formed with a peripheral array of outwardly projectingblades displaceable on said rotor to intercept said path and rotatablein a direction opposite the direction in which said grain is projectedby said impeller; and at least one array of repeller blades attached tosaid housing for intercepting grain entrained by said impact motor andcooperating therewith to comminute the grain.
 2. The grain comminuterdefined in claim 1 wherein said impeller is a rotor provided with fanblades and is rotated in one sense for sweeping said grain along oneside of the impeller rotor, said comminuter further comprising aregulator extending from said opening along said side of said impellerfor controlling the rate of flow of the grain therethrough, said impactrotor being formed along its periphery with angularly spaced slots, eachreceiving an array of toothed impact blades separated by spacer lamellaeestablishing the distance between the toothed blades, said impact rotorbeing positioned to bring the side thereof opposite the side of theimpeller rotor into engagement with the grain, said repeller bladesbeing rotatably adjustable to replace the effective cutting edgesthereof.